Face ID is a facial security technology similar to Touch ID (fingerprint sensor), which was first released by Apple on the iPhone X generation. It is used as an authentication method for the process. log a number of applications such as: application bank customers or applications online shopping easier and takes less time.
iOS 12
However, we should remove Face ID on some applications to protect personal information. Here's an article on how to remove Face ID on iPhone applications, invite you to refer.
Disable Face ID on iPhone apps
Step 1: Go to Settings (Settings), and then choose Face ID & Passcode (Face ID and Security).

Step 2: Enter your Face ID password , then select Other Apps . A list of applications that use this feature will appear, as well as their current status.

Step 3: Switch the switch to off on the app you want to disable the right to use Face ID .

In addition, you can use the following method to remove Face ID on iPhone applications, the effect is similar to the above.
Step 1: Go to Settings (Settings), and then select the application you want to turn off Face ID.

Step 2: In Face ID , turn the switch to off.

Above is a guide to removing Face ID on some iPhone applications, in addition, you can refer to some articles about this face recognition feature such as: Fixing Face ID errors , Using Face ID on Android ...